1. Field of the Invention
The invention relates to vehicle braking systems; and, more particularly, to a vehicle brake hose system with a whip dampener for eliminating pulsation and uneven wear of vehicle brake systems that meets Department of Transportation standards.
2. Description of the Prior Art
In order to accommodate necessary relative motion between the sprung and unsprung masses of a motor vehicle (i.e., the chassis and suspended wheels), suspension mounted hydraulic brakes are connected to the chassis by flexible hydraulic hoses. These hoses are typically fabricated from fabric braid reinforced elastomers.
Standard original equipment of such fabric reinforced flexible brake hoses on motor vehicles expand or swell to some extent under pressure, thus using up some of the available brake pedal travel and resulting in a relatively "soft" feel to the brake pedal. This soft feel reduces the precision of brake modulation by the driver. Both of these conditions are unacceptable in racing cars. For more than a quarter of a century, racing cars have been equipped with flexible brake hoses of stainless steel braid protected extruded Teflon. These hoses exhibit considerably less expansion under pressure resulting in a higher and firmer brake pedal and a larger margin of safety in the case of more even friction pad wear and more precise brake modulation.
Despite an outstanding record of performance and reliability in racing and off highway use, these high performance flexible brake hoses have not been certified for highway use because they have been unable to comply with the Basic Motor Vehicle Safety Standard 106, Section 56.3 (whip resistance test) set by the U.S. Department of Transportation (DOT).
Thus, efforts made in the past to substitute stainless steel braid protected Teflon flexible hose for the original equipment elastomeric brake hose on vehicles has usually led to fatigue failure of the protective braid at the end of the crimp or swedged collar or socket of the hose end fitting followed by fatigue failure of the Teflon hose and resultant loss of pressure. Applicant is not aware of any substitute that is able to pass the aforementioned whip resistance test required by DOT for highway use vehicles.
There is thus a need for a flexible brake hose assembly that accommodates necessary relative motion between the chassis and wheels of a vehicle and passes all aspects of the whip resistance test required by the DOT.